Lumbar pain holds one of the leading positions of prevalence in the world. The common cause of vertebrogenic pain syndrome is spondylarthrosis. Conservative management of spondylarthrosis does not consistently provide an evident therapeutic effect. Open surgical treatment of spondylarthrosis also has a number of disadvantages due to a high risk of postoperative complications and high injury rate. Experimental determination of optimal operational modes of the devices for laser osteoperforation of lumbar facet joints was the purpose of this study. The experiment was performed in March 2020. Within the experiment, laser osteoperforation of lumbar facet joints was performed in experimental animals (mini pigs) with simultaneous measurement of the temperature on the surface and within the tissue and with further histological examination of bone material. The Ethics Committee Approval for the experiment was preliminarily obtained. The highest temperature of 79 °С was registered while performing open laser osteoperforation of the facet joint. Eventually, the following optimal operational modes of laser devices were determined: 2.0 W in continuous mode for radiation with the wavelength of 0.97 µm, and 5.0 W in pulse-periodic mode for radiation with the wavelength of 1.56 µm at the pulse length of 100.0 ms and the pause length of 50.0 ms. Histological examination results were obtained. The optimal modes of laser exposure while performing osteoperforation of facet joints were experimentally worked through and determined, which was further proven by the histological examination data. It makes sense to continue the exploratory development to implement the method in clinical practice.

Objective: to select optimal parameters of two-wave near-infrared laser irradiation for the arthroscopic treatment of chondromalacia foci in the articular cartilage. Material and methods. Bull articular cartilages were treated with laser light delivered by a fifi ber and having various parameters. Human articular cartilages with chondromalacia foci taken during the total knee replacement were also treated with laser light delivered by a fifi ber and having various parameters. The processed cartilage samples were examined macroscopically and then histologically. Changes in the structure of ar[1] ticular cartilage after laser irradiation were assessed. Results. A two-second irradiation with two-wave laser light (λ = 0.97 μm / 30 W and λ = 1.55 μm / 15 W) causes a rapid “melting” of lesion margins without macroscopically visible carbonization with a wide thermally affected zone in the irradiated area. Histologically, cartilage preparations irradiated with two-wave laser light (wavelengths λ = 1.55 μm / 5 W and λ = 0.97 μm / 3 W) for 2 sec demonstrated slight changes in the cartilage structure without thermal destruction of chondrocytes. Conclusion. The optimal combination for laser irradiation of the cartilage tissue in the saline solution environment which restores articular cartilage shape is two-wave laser light λ = 0.97 μm at power of 3 W and λ = 1.55 μm at power of 5 W from the distance of 1–2 mm under 2 sec exposure.

Background: The present study focuses on investigation of Intra-articular PDT mechanisms for OA treatment. Also, a search for determination of the most effective dose of chlorin e6 (Ce6) for anti-inflammatory PDT of OA was carried out. Methods: The study was carried out on laboratory animals (11 Chinchilla rabbits, 1 year, 2.5 kg) with a gonarthritis model of post-traumatic OA. According to the instructions for using Photoditazin (Ce6 based PS) for PDT of human oncological and non-oncological diseases, the recommended dose is 0.7-1.2 mg/kg. For studies on rabbits, taking into account the conversion coefficient (3.2), the PS doses of 2.4, 3.2 and 6.4 mg/kg were selected. Fluorescence spectra were measured intra-articular before and after PDT using spectrometer with fiber-optic probe. The intrajoint PDT was carried out using a laser (662 +/- 10 nm) and a fiber-optic catheter with a cylindrical diffuser inside a sapphire needle for a uniform distribution of the laser radiation. The immunohistochemical study was carried out by staining the samples with caspase-3. Results: Histological and immunohistochemical analysis showed that the best PS dose for intravenous administration for PDT of rabbit gonarthritis is 3.2 mg/kg. The PS concentration directly in the synovial tissue was 0.5 mg/kg, and this was enough to achieve the most positive results to reduce the caspase-3 level. Conclusion: The caspase-3 level correlates well with other signs of inflammation in the synovial membrane (edema, etc.). Therefore, to assess the PDT effectiveness in the treatment of gonarthritis accompanied by synovitis, it is sufficient to analyze only for caspase-3. The efficacy of PDT with Ce6 showed that 3.2 mg/kg PS dose (1 mg/kg for a human) is the most effective.

This study focuses on investigation of intra-articular photodynamic therapy (PDT) mechanisms for osteoarthritis (OA) treatment. Also, a search for determination of the most effective dose of photosensitizer (PS) chlorine e6 (Ce6) for anti-inflammatory PDT of OA was carried out. It was found that to assess the PDT effectiveness in the treatment of OA accompanied by synovitis, it is sufficient to analyze for caspase-3 with the condition that the biopsy sample is taken 2-3 days after PDT. The results of the study on the efficacy of PDT with Photoditazin at various administered doses in the treatment of OA showed that 3.2 mg/kg PS dose (1 mg/kg for a human) is the most effective.

Background: The new methods of osteoarthritis treatment are in constant demand due to the complexity of the early diagnosis and therapy. Specific features of Chlorin e6 derivative (Ce6) accumulation in knee joint tissues and the efficiency of photodynamic therapy (PDT) of gonarthritis were studied.Methods: The experimental research was conducted on the model of posttraumatic gonarthritis on rabbits. The analysis of dynamics of change of Ce6 concentration in tissues of a knee joint was carried out by the method of fluorescent diagnostics. The intra-joint PDT was carried out using 662 nm laser with energy density of 120-150 j/cm(2) and a sapphire diffuser. An analysis of slices was conducted to confirm the anti-inflammatory effect through apoptosis.Results: The method of fluorescent spectroscopy revealed that the highest amount of Ce6 was accumulated in the synovial membrane of a damaged knee joint 2.5 h after its intravenous introduction. On 14th day after gonarthritis modeling but before PDT the synovial membrane showed signs of synovitis. On 21st day after PDT the synovial membrane possessed noticeable villous structure, and no cells of inflammatory nature were observed.Conclusion: Fluorescent diagnostics in knee joint tissues can be used in clinical practice of gonarthritis before, during and after PDT for monitoring the Ce6 accumulation and for treatment control. Optimal radiation energy density was determined to be 150 j/cm(2). In the studied time intervals (5-25 min) no dependency of PDT effect on irradiation time at the same energy density was observed. The analysis of results of clinical and morphological research shows that PDT is a low-invasive method of gonarthritis treatment with a high degree of efficiency and selectivity. (C) 2016 Elsevier B.V. All rights reserved.